The chapters in this monograph are contributions from the Advances in Quantum Monte Carlo symposium held at Pacifichem 2010, International Chemical Congress of Pacific Basin Societies. The symposium was dedicated to celebrate the career of James B. Anderson, a notable researcher in the field. Quantum Monte Carlo provides an ab initio solution to the Schroedinger equation by performing a random walk through configuration space in imaginary time. Benchmark calculations suggest that its most commonly-used variant, "fixed-node" diffusion Monte Carlo, estimates energies with an accuracy comparable to that of high-level coupled-cluster calculations. These two methods, each having advantages and disadvantages, are complementary "gold-standards" of quantum chemistry. There are challenges facing researchers in the field, several of which are addressed in the chapters in this monograph. These include improving the accuracy and precision of quantum Monte Carlo calculations; understanding the exchange nodes and utilizing the simulated electron distribution; extending the method to large and/or experimentally-challenging systems; and developing hybrid molecular mechanics/dynamics and Monte Carlo algorithms.

Professionals recognize entropy-enthalpy compensation as an important factor in molecular recognition, lead design, water networks, and protein engineering. It can be experimentally studied by proper combinations of diverse spectroscopic approaches with isothermal titration calorimetry and is clearly related to molecular dynamics. So, how should we treat entropy-enthalpy compensation? Is it a stubborn hindrance that solely complicates the predictability of phenomena otherwise laid on the line by Mother Nature? How should we then deal with it? This book dwells on these posers. It combines two chapters written by globally recognized specialists. Chapter 1 deals with general issues and suggests a definite approach to how we may answer the posers. Chapter 2 shows how the approach outlined might be successfully applied in a rational design of enzymes. This might provide other interesting strategic perspectives in the general theoretical physical chemistry field.

This book covers recent advances of the fragment molecular orbital (FMO) method, consisting of 5 parts and a total of 30 chapters written by FMO experts. The FMO method is a promising way to calculate large-scale molecular systems such as proteins in a quantum mechanical framework. The highly efficient parallelism deserves being considered the principal advantage of FMO calculations. Additionally, the FMO method can be employed as an analysis tool by using the inter-fragment (pairwise) interaction energies, among others, and this feature has been utilized well in biophysical and pharmaceutical chemistry. In recent years, the methodological developments of FMO have been remarkable, and both reliability and applicability have been enhanced, in particular, for non-bio problems. The current trend of the parallel computing facility is of the many-core type, and adaptation to modern computer environments has been explored as well. In this book, a historical review of FMO and comparison to other methods are provided in Part I (two chapters) and major FMO programs (GAMESS-US, ABINIT-MP, PAICS and OpenFMO) are described in Part II (four chapters). dedicated to pharmaceutical activities (twelve chapters). A variety of new applications with methodological breakthroughs are introduced in Part IV (six chapters). Finally, computer and information science-oriented topics including massively parallel computation and machine learning are addressed in Part V (six chapters). Many color figures and illustrations are included. Readers can refer to this book in its entirety as a practical textbook of the FMO method or read only the chapters of greatest interest to them.

This book covers recent advances of the fragment molecular orbital (FMO) method, consisting of 5 parts and a total of 30 chapters written by FMO experts. The FMO method is a promising way to calculate large-scale molecular systems such as proteins in a quantum mechanical framework. The highly efficient parallelism deserves being considered the principal advantage of FMO calculations. Additionally, the FMO method can be employed as an analysis tool by using the inter-fragment (pairwise) interaction energies, among others, and this feature has been utilized well in biophysical and pharmaceutical chemistry. In recent years, the methodological developments of FMO have been remarkable, and both reliability and applicability have been enhanced, in particular, for non-bio problems. The current trend of the parallel computing facility is of the many-core type, and adaptation to modern computer environments has been explored as well. In this book, a historical review of FMO and comparison to other methods are provided in Part I (two chapters) and major FMO programs (GAMESS-US, ABINIT-MP, PAICS and OpenFMO) are described in Part II (four chapters). dedicated to pharmaceutical activities (twelve chapters). A variety of new applications with methodological breakthroughs are introduced in Part IV (six chapters). Finally, computer and information science-oriented topics including massively parallel computation and machine learning are addressed in Part V (six chapters). Many color figures and illustrations are included. Readers can refer to this book in its entirety as a practical textbook of the FMO method or read only the chapters of greatest interest to them.